Modifiers are not removed while overriding variables

[niggeulimann]

We have a quite huge multi theme setup - we have values for each customer/theme and semantic vars which uses modifiers:
e.g.

{ "test": { "value": "#ffffff", "type": "color", "$extensions": { "studio.tokens": { "modify": { "type": "darken", "value": ".25", "space": "srgb" } } } } }

Some of those customers/themes will override these “default-vars” afterwards e.g.:
"test": { "value": "#ff0000", "type": "color" }
Unfortunately the modifiers are not removed in this case:
The export-script uses the right color #ff000 in this case, but additionally adds the modifier.

see issue in Configurator

[jorenbroekema]

Offending code is somewhere in here: https://github.com/amzn/style-dictionary/blob/v4/lib/utils/deepExtend.js

When deep extending objects, we don't seem to take into account that merging:

{
  "test": {
    "value": "#ffffff",
    "type": "color",
    "$extensions": {
      "studio.tokens": {
        "modify": {
          "type": "darken",
          "value": ".25",
          "space": "srgb"
        }
      }
    }
  }
}

with

{
  "test": {
    "value": "#ff0000",
    "type": "color"
  }
}

should result in

{
  "test": {
    "value": "#ff0000",
    "type": "color"
  }
}

and not in

{
  "test": {
    "value": "#ff0000",
    "type": "color",
    "$extensions": {
      "studio.tokens": {
        "modify": {
          "type": "darken",
          "value": ".25",
          "space": "srgb"
        }
      }
    }
  }
}

[niggeulimann]

Hey @jorenbroekema, thank you a lot!

Is V4 already ready for production?

[jorenbroekema]

No its API is not yet stable, still a small amount of things coming that I think will be API breaking. It's a bit tricky to answer because V4 already solves a loooot of issues with V3 so staying on V3 might be more problematic than migrating to unstable V4 and doing another small migration to the final V4 when it releases (estimated in June)